Test compounds are screened in hypertransfused BDF1 male mice under standard conditions developed at this Institute. Animals are quarantined for one week, hypertransfused with washed, heated canine red blood cells in the second week, then treated once daily by the intraperitoneal or oral route for seven days with the test compound. The mice are observed for gross toxic signs during treatment and at necropsy. Individual weighed spleens, and livers and pooled samples of daily collected and measured fecal and urinary specimens are analyzed for iron content by atomic absorption spectroscopy. Iron-chelation effectiveness of test compounds is compared directly with a bioassay internal standard, Desferal (used clinically). The same two dogs are used as blood donors and their health is monitored frequently.